Device for accomodating a tool or a support element in a machine tool or a spindle

ABSTRACT

A device for receiving a tool or support element in a machine tool or spindle has a tool carrier receiving member arranged in a machine tool or spindle and a tool carrier having a tool receiving member for a tool as well as a clamping device for securing the tool carrier in the tool carrier receiving member. The tool carrier has two areas, wherein a first area includes the tool receiving member and wherein a second area is designed to be received in the tool carrier receiving member. The second area includes the clamping device. The two areas are merged with one another in the axial direction of the device by overlapping the areas.

BACKGROUND OF THE INVENTION

The invention relates to a device for accommodating a tool or a supportelement in a machine tool or spindle, the device comprising a toolcarrier receiving member arranged at the machine tool or spindle,comprising a tool carrier having a tool receiving member for the tool aswell as a clamping device for fixation of the tool carrier at the toolcarrier receiving member.

Known devices for receiving a driven or stationary tool (for example, acutting tool) or any other parts (for example, a support element for ameasuring device) in a machine tool or spindle have a tool carrierreceiving member which is either arranged as a separate part at themachine tool or is a part of the machine tool itself. Furthermore, atool carrier is provided which has a tool receiving member for the tool.In order to be able to securely connect this tool carrier receivingmember with the tool carrier in a permanent manner, a clamping device isprovided. For this purpose, the tool carrier is divided into two areas,i.e., a first area for the tool receiving member and a second area to bereceived in the machine part or spindle part whereby in this second areathe clamping device is arranged in the interior of the tool carrier.This arrangement of the clamping device results in the total length ofthe tool carrier being the sum of the two aforementioned areas. As aresult of machine tools that have been recently introduced into themarket and have a more limited work space the large constructive size ofthe tool carrier is disadvantageous.

It is therefore an object of the invention to provide a tool carrier ofa short length.

SUMMARY OF THE INVENTION

As a technical solution it is suggested with the invention that the twoareas of the tool carrier i.e., the tool receiving member as well as thearea to be received in the tool carrier receiving member including theclamping device, are merged in the axial direction by overlapping theirlongitudinal areas.

This provides a tool carrier changing system of a compact design forrotating as well as stationery tools or for any other parts (forexample, for a support element for a measuring device). The basic ideaof the inventive tool carrier changing system is that the two areas ofthe tool carrier, i.e., the area for the tool receiving member and thearea to be received in the machine part or the spindle part, are mergedwith one another. This is to be understood such that the two areas areradially spaced from one another, whereby the area for the toolreceiving member is positioned inwardly, that however, in the axialdirection the areas overlap. The inventive integration of the toolreceiving member of the tool carrier into the area of the tool carrierreceiving member results in the aforementioned advantage of a shortlength. This short length furthermore results in minimal torque at theinterface caused by the transverse forces during machining and thusprovide a very stiff basic construction. Furthermore, for the axial toolpreadjustments the adjusting elements are freely accessible from therear. Moreover, it is possible with a suitable embodiment of theclamping device to provide very high pretension. Finally, theconstruction makes it possible for driven tools to arrange the toolcarrier receiving member below the first spindle bearing. This resultsin short leverage, minimal deformation and yielding. Overall, a veryshort device thus is provided with the tool carrier as a continuousmodular tool system that allows to employ on multi spindle machines andin connection with all other machines within shortest constructivespaces to use tool changing systems with the aforementioned advantagesof the known systems.

An advantageous embodiment suggests that as a clamping device a clampingring is to be provided at the exterior of the tool carrier which engagesdirectly or indirectly and which secures the tool carrier between it andthe tool carrier receiving member. The basic principle is that theclamping device is not arranged in the interior of the tool carrieradjacent to the tool receiving member but to provide as a clampingdevice a clamping ring which is positioned externally at the housing ofthe tool carrier and thus can thus be located in the samecross-sectional plane as the tool receiving member. Accordingly, themerging of the two areas of the tool carrier is realized. The inventivedevice has thus three principle components, i.e., the tool carrierreceiving member, furthermore, the actual tool carrier, and finally thetool carrier clamping device in connection with the inventive clampingring. The tool carrier receiving member may have a cylindrical centeringdevice with a planar end face stop, the tool carrier may have acentering cylinder also with a planar end face stop and a tool receivingmember as well as finally the clamping ring as a fastening means.Inasmuch as the clamping ring engages directly the tool carrier, adirect mechanical contact between the clamping ring and the tool carrieris provided. An indirect engagement of the clamping ring at the toolcarrier is to be understood such that an additional intermediate elementis positioned between the clamping ring and the tool carrier which istransferred by the clamping ring into the securing position and is thenresponsible for the securing of the tool carrier between the toolcarrier receiving member and the clamping ring.

An advantageous embodiment suggests that the clamping ring has aradially inwardly oriented abutment surface as a direct or indirectcounter surface to a corresponding abutment surface of the tool carrier.This provides a technically simple solution in order to secure by theinventive clamping ring the tool carrier between the clamping ring andthe tool carrier receiving member. In the “direct” variant the abutmentsurface engages directly at the corresponding contour abutment surfaceof the tool carrier. In the “indirect” variant intermediate elements areprovided between the abutment surface of the clamping ring and thecounter abutment surface of the tool carrier, as will be explained inthe following.

A further embodiment for a “direct” variant suggests that the abutmentsurface of the clamping ring has an inner diameter that is smaller thanthe outer diameter of the tool carrier. The clamping ring is thusembodied relative to its radial contour such that due to thecorresponding end face contour of the tool carrier the latter is forcedby the clamping ring by a positive-locking connection against the toolcarrier receiving member.

An “indirect” variant suggests that the abutment surface of the clampingring has an inner diameter that is greater than the outer diameter ofthe tool carrier, that the abutment surface at its inner side toward theaxis of the clamping ring has a slanted guide surface, and that in thearea of the abutment surface of the clamping ring a securing element isarranged which, in the initial position without fixation of the clampingring, has a greater inner diameter than the outer diameter of the toolcarrier and which, after transfer of the clamping ring into the securingposition has a smaller inner diameter than the outer diameter of thetool carrier. The basic principle of this “indirect” variant is that theclamping ring upon changing the tool carrier must not be completelyremoved but must only be loosened to such an extent that the securingelement or securing elements have widened so much that the exchangeabletool carrier is released and can be removed through the front opening ofthe clamping ring. The abutment surface in this context is substantiallyconical whereby the tip of the cone is positioned on the axis of theclamping ring counter to the direction of transfer of the clamping ringinto the securing position. This means that upon transfer of theclamping ring into the securing position the cross-section of theclamping ring in the area of the slanted guide surface is reduced withthe effect that the securing element is moved radially inwardly,resulting in a diameter reduction.

As a securing element a slotted spring ring can be provided, especiallya steel ring. With this special arrangement it is possible to insert thetool carrier in the loosened position into the tool carrier receivingmember. The subsequent tightening of the clamping ring with theresulting axial movement then moves the metal ring along the slantprovided at the clamping ring inwardly and brings it into abutment atthe shoulder of the tool carrier.

As an alternative, the securing elements may also be pivotable levers.Advantageously, about the periphery of the tool carrier a plurality ofsuch levers are arranged. The levers act as clamping segments which aremoved inwardly by the clamping ring into the clamping position so thatthe levers engage across the tool carrier and secure it thereby. In therelease position, the levers can be opened by pivoting them outwardly tosuch an extent that the diameter of the tool carrier will pass through.The design of the clamping elements moreover provides an additionalforce increase.

Preferably, the levers are pivoted outwardly by a spring element in thespring-loaded basic position. The spring element may be, for example, anO ring.

As an alternative it is suggested that the securing element is a springring with lever-like spring tongues. The basic idea is the same as withthe aforementioned levers. In this (the last) alternative, the leverscan be imagined as part of a spring ring whereby the individual leversare produced by cuts in the complete spring ring. The ring is comprisedof spring steel, and the levers are thus essentially spring tongues. Theclamping ring then pivots the spring tongues inwardly into the clampingposition.

A further embodiment of the inventive device suggests that the clampingring is threaded by a thread directly onto the tool carrier receivingmember and/or by a bayonet closure directly onto the tool carrierreceiving member. This provides a simple possibility for the arrangementand force transmission of the clamping ring with respect to connectingto the tool carrier receiving member.

In an alternative it is also possible that the spring ring is axiallymovable by a clamping nut. In this case, the clamping nut must bethreaded externally onto the clamping ring. The combination of aleft-handed thread with a right handed thread can result in travelstroke doubling.

BRIEF DESCRIPTION OF THE DRAWINGS

Three embodiments of the inventive device with reception of a tool in amachine tool is disclosed in the following with the aid of the drawings.It is shown in:

FIG. 1 in longitudinal section a first embodiment in an exploded view;

FIG. 2 the device of FIG. 1 in the assembled state;

FIG. 3 a second embodiment with a slotted steel ring;

FIG. 4 a third embodiment with pivotal levers in the securing position;

FIG. 5 a representation based on FIG. 4 but in the open position.

DESCRIPTION OF PREFERRED EMBODIMENTS

In FIGS. 1 and 2 a first embodiment, in FIG. 3 a second embodiment, andin FIGS. 4 and 5 a third embodiment of the inventive device forreceiving a tool in a machine tool is represented.

The first embodiment in FIGS. 1 and 2 comprises a tool carrier receivingmember 1 which is correlated with a non-represented machine tool. Thistool carrier receiving member 1 has a cylindrical centering device 2 aswell as a planar end face stop 3 and furthermore a bolt-shaped fixation4 for receiving excessive torque and for angular alignment as well as acounter thread 5 for a tool carrier clamping device.

As a further component a tool carrier 6 is provided. This tool carrier 6has a centering cylinder 7 as well as a planar end face stop 8, andfurthermore a cutout 9 for position fixations, matching the bolt-shapedfixation 4 of the tool carrier receiving member 1, a tool receivingmember 10, an axial basic adjusting device 11 for the tools, channels 12for the cooling medium as well as an abutment surface 13 for the toolcarrier clamping action.

Finally, the tool carrier changing system for the tool carrier devicehas a clamping ring 14 which engages about the tool carrier 6. Itcomprises a radially inwardly directed abutment surface 15 and for thispurpose is crimped radially inwardly with an L-shaped cross-sectionalprofile. Furthermore, the clamping ring 14 has inner thread 16.

The tool carrier changing system in the first embodiment of FIGS. 1 and2 functions as follows.

The tool carrier 6 is inserted with its centering cylinder 7 into thecylindrical centering device 2 of the tool carrier receiving member 1.The planar end face stop 8 of the tool carrier 6 comes into contact withthe planar end face stop 3 of the tool carrier receiving member 1.Furthermore, the cutout 9 of the tool carrier 6 will come to rest at thebolt-shaped position fixation 4 of the tool carrier receiving member 1.Subsequently, the clamping ring 14 with its inner thread 16 is threadedonto the counter thread 5 of the tool carrier receiving member 1 to suchan extent that the abutment surface 15 of the clamping ring 14 will cometo rest at the abutment surface 13 of the tool carrier 6 so that thetool carrier 6 is secured between the tool carrier receiving member 1and the clamping ring 14. When a change of the tool carrier 6 isdesired, the clamping ring 14 is removed and after changing of the toolcarrier 6 is again threaded thereon.

The embodiment in FIG. 3 has the same basic components tool carrierreceiving member 1, tool carrier 6, and clamping ring 14. While in thefirst embodiment of FIGS. 1 and 2 the inner diameter of the clampingring 14 in the area of the abutment surface 15 was smaller than theouter diameter of the tool carrier 6, in this second embodiment of FIG.3 the inner diameter of the clamping ring 14 in the area of the abutmentsurface 15 is greater than the outer diameter of the tool carrier 6. Thedifference lies in that in the second embodiment the abutment surface 15is embodied as a guide surface 17 and that, furthermore, a slottedspring ring 18 made of metal is provided.

The function of this second embodiment of FIG. 3 is as follows.

FIG. 3 shows in the left half the state of the device before securing ofthe tool carrier 6 at the tool carrier receiving member 1. It can beseen that the ring 18 rests at the inner mantle surface of the clampingring 14 by its own tension and that the inner diameter of the ring 18 isgreater than the outer diameter of the tool carrier 6. When threadingthe clamping ring 14 into the securing position, the ring 18 is radiallymoved inwardly by the guide surface 17 at the clamping ring 14 so thatsuch an inner diameter reduction results that the ring 18 will come torest at the shoulder of the tool carrier 6 such that it can no longerpass through the end face opening in the clamping ring 14. This is shownin FIG. 3 in the right half.

The advantage of such an embodiment is that for changing the toolcarrier 6 the clamping ring 14 must not completely be removed from thetool carrier receiving member 1. It is only required to move theclamping ring 14 by a few revolutions such in the axial direction thatthe ring 18 has its maximum diameter position. In this position, thetool carrier 6 can then be removed from the tool carrier receivingmember 1 and can be exchanged for another tool carrier 6.

The third embodiment in FIGS. 4 and 5 is based, in principle, on thesame design as the second embodiment of FIG. 3. Instead of the slottedring 18, levers 19 are provided which are pivotal at a rolling surfacewithin the tool carrier receiving member 1. Furthermore, one springelement 20 in the form of an O-ring pushes the lever 19 outwardly. Thefree ends of the levers 19 are angled relative to the axis A of theclamping ring 14 and correspond to the slanted guide surface 17 of theclamping ring 14. The clamping ring 14 is actuated, i.e., moved in theaxial direction, by a clamping nut 21 which in the area of the toolcarrier receiving member 1 has a left-handed thread and in the area ofthe clamping ring 14 a right-handed thread (or vice versa).

The third embodiment in FIGS. 4 and 5 functions as follows.

The securing position is represented in FIG. 4, i.e., the clamping ring14 is in its secured position in which the guide surface 14 of theclamping ring 14 has pivoted the lever 19 inwardly to such an extentthat the angled ends of the levers 19 engage the tool carrier 6 to besecured. In order to change the tool carrier 6, the clamping nut 21 isrotated such that the clamping ring 14 will perform a travel stroke. Theoppositely oriented threads of the clamping nut 21 results in a doublingof the travel stroke length. The stroke movement of the clamping ring 14pivots the levers 19 outwardly to thus release the tool carrier 6 sothat it can be removed from the tool carrier receiving member 1.

The advantage of this third embodiment is that for changing the toolcarrier 6 the clamping ring 14 must not be completely removed. It isonly necessary to move the clamping ring 14 by a small amount in theaxial directions so that the tool carrier 6 can be removed.

The specification incorporates by reference the entire disclosure ofGerman priority document 197 30 584.9 of Jul. 17, 1997, as well as ofInternational Application PCT/DE98/02052 of Jul. 17, 1998.

The present invention is, of course, in no way restricted to thespecific disclosure of the specification and drawings, but alsoencompasses any modifications within the scope of the appended claims.

List of Reference Numerals

1 Tool carrier receiving member

2 Cylindrical centering device

3 Planar end face stop

4 Bolt-shaped position fixation

5 Counter thread

6 Tool carrier

7 Centering cylinder

8 Planar end face stop

9 Cutout

10 Tool receiving member

11 Axial adjusting device

12 Channel

13 Abutment surface

14 Clamping ring

15 Abutment surface

16 Inner thread

17 Guide surface

18 Ring

19 Lever

20 Spring element

21 Clamping nut

A Axis

What is claimed is:
 1. Device for receiving a tool or support element ina machine tool or spindle, said device comprising: a tool carrierreceiving member (1) arranged in a machine tool or spindle; a toolcarrier (6) having a tool receiving member (10) for a tool and having aclamping device (14, 18, 19, 21) for securing said tool carrier (6) insaid tool carrier receiving member (1); said tool carrier (6) having twoareas, wherein a first one of said areas comprises said tool receivingmember (10) and wherein a second one of said areas is designed to bereceived in said tool carrier receiving member (1) and comprises saidclamping device (14, 18, 19, 21); wherein said two areas are merged withone another in an axial direction of said device by overlapping of saidareas; and wherein said tool carrier receiving member (1) and said toolholder (6) each have a planar end face stop (3, 8), respectively, saidplanar end stops (3, 8) fitted into one another when said tool carrierreceiving member (1) and said tool carrier (6) come into contact. 2.Device according to claim 1, wherein said clamping device comprises aclamping ring (14) engaging a periphery of said tool carrier (6)directly or indirectly, wherein said clamping ring (14) secures saidtool carrier (6) between said clamping ring (14) and said tool carrierreceiving member (1).
 3. Device according to claim 1, wherein saidclamping ring (14) has a radially inwardly oriented abutment surface(15) and wherein said tool carrier (6) has a matching counter abutmentsurface (13), wherein said abutment surface (15) of said clamping ring(14) engages directly or indirectly said counter abutment surface (13)of said tool carrier (6).
 4. Device according to claim 3, wherein saidabutment surface (15) of said clamping ring (14) has an inner diameterthat is smaller than an outer diameter of said tool carrier (6). 5.Device according to claim 3, wherein: said abutment surface (15) of saidclamping ring (14) has an inner diameter that is greater than an outerdiameter of said tool carrier (6); said abutment surface (15) of saidclamping ring (14) has an inner side facing an axis (A) of said clampingring (14); said inner side has a slanted guide surface (17); saidclamping device further comprises a securing element (18, 19, 20)arranged in the area of said abutment surface (15) of said clamping ring(14); said securing element (18, 19, 20), in a non-securing initialposition of said clamping ring (14), has an inner diameter that isgreater than an outer diameter of said tool carrier (6); said securingelement (18, 19, 20), after transfer of said clamping ring (14) into asecuring position, has an inner diameter that is smaller than said outerdiameter of said tool carrier (6).
 6. Device according to claim 5,wherein said securing element is a slotted spring ring (18).
 7. Deviceaccording to claim 5, wherein said securing element comprises pivotablelevers (19).
 8. Device according to claim 7, wherein said securingelement further comprises a spring element (20) and wherein said levers(19) are pivoted outwardly by said spring element (20) from aspring-loaded basic position.
 9. Device according to claim 2, whereinsaid clamping ring (14) has a first thread (16) and wherein said toolcarrier receiving member (1) has second thread (5) matching said firstthread (16), wherein said clamping ring (4) and said tool carrierreceiving member (1) are connected by threading said clamping ring (14)onto said tool carrier receiving member (1).
 10. Device according toclaim 2, wherein said clamping device further comprises a clamping nut(21) and wherein said clamping ring (14) is axially adjustable by saidclamping nut (21).
 11. The device according to claim 1, wherein theplanar end face stop (3) of the tool carrier receiving member (1) has abolt-shaped fixation (4) and the planar end face stop (8) of the toolcarrier (6) has a corresponding cutout (9) for said fixation (4).